Learn more about this topic at the 2018 Cattle Raisers Convention, March 23-25, 2018 at the Fort Worth Convention Center. For more information, visit www.cattleraisersconvention.com.
By Robert Fears
The Cattle Raisers Convention opens in Fort Worth next month and it’s one you don’t want to miss. There are numerous good reasons to attend, including the opportunity to attend the School for Successful Ranching.
Topics were carefully selected to provide ideas for improving operation efficiency and increasing profit.
One example is a planned discussion on growing and managing year-round pastures led by Dr. David Bade, a retired professor and Extension forage specialist from Texas A&M AgriLife Extension and currently with Pennington Seed Company. This article previews a portion of Bade’s presentation.
Feed costs are often an overwhelming expense for producers who don’t grow and manage year-round pastures. It is possible to eliminate or greatly reduce supplemental feeding by maintaining the forage quantity and quality to match animal requirements.
In Texas, forages vary in quantity and quality throughout the year in response to climatic conditions, soil types and management. Variation is also due to the type of forage and the selected variety. Forage quality refers to digestible nutrient content, such as crude protein (CP) and energy (total digestible nutrients or TDN), digestibility and palatability.
Forage types and plant species
Forage types are legumes, cool-season annual grasses, cool-season perennial grasses, warm-season annual grasses and warm-season perennial grasses.
Legumes (alfalfa, medics, clovers, vetch) are the highest quality group with good CP, TDN and mineral content. Rhizobia bacteria live in nodules on legume roots and convert N2 from the atmosphere into NH3, a form of nitrogen used by plants. Since legumes produce their own nitrogen, they are economical to grow because they don’t require fertilizer for their source of nitrogen.
The high forage quality can make a big difference in animal performance, even if legume production is limited. A limited stand of legumes provides as much nutrition as feeding range cubes to cattle consuming dormant grass or dry hay.
Legume varieties are region- and soil-specific, so check with your county Extension agent for recommendations on what to plant.
Most legumes grown in Texas are fall-planted, reseeding annuals. They provide limited forage in December through February with most of their production occurring from February through April or May, depending on the variety.
The second highest-quality group of forage plants are cool-season annual grasses such as oats, rye, ryegrass and wheat.
Manage these plants to produce forage in December through February, even though they typically produce forage in March through April. Producing early forage for winter grazing requires Sept. 15 to Oct. 1 planting in a prepared seedbed or overseeding pastures, using proper seed and fertilizer rates and managing grazing in a way to utilize winter forage in the fall.
Perennial cool-season grasses have limited use in Texas, but endophyte-safe tall fescue is a good winter pasture alternative where it is adapted. It eliminates the yearly planting of annual cool-season grasses and has fairly high forage quality.
Warm-season annual grasses, such as Sudan and forage sorghums, offer higher digestibility than warm-season perennial plants, but their production period is shorter. They maintain a relatively high carrying capacity of 2 or 3 animals per acre for 30 to 45 days. As an annual plant, it is expensive because it requires yearly land preparation and seeding. The prime role of warm-season annual plants in forage production is for high-quality hay.
The lowest quality forage group is the warm-season perennial grasses such as bermuda, bahia, klein and bluestem. These grasses are, however, the group that is best suited for the Texas climate and most productive quantitatively.
Management for increased quality is very important because normally, warm-season grass barely meets or is below animal nutrient requirements during the grazing season. A 1 percent increase in digestible energy can result in a 5 percent increase in animal performance.
Management to increase forage quality includes variety selection, harvesting at proper plant maturity, weed control, fertilization and implementation of grazing plans that promote optimal forage utilization.
Warm-season grass nutrition varies greatly during the growing season, with the highest quality in the spring. Quality declines from June through August, then increases in September to October or November and rapidly declines after the first freeze. The better a grass variety is adapted to soil, climatic and management conditions, the better it sustains production.
Plant maturity
As forage plants mature, forage quality decreases.
Immature or young plants are composed of mostly leaves, which are highly digestible. As grass matures, vegetative growth gives way to production of stems and seed heads.
Older leaves and stems of mature plants are higher in hard-to-digest fiber.
For example, 12-inch tall coastal bermudagrass is approximately 58 percent digestible in the top third of the plant, 54 percent in the middle third and only 50 percent digestible in the bottom third.
Fertilization
Proper fertilization results in vigorous plant growth. Fertilize pastures according to recommendations from soil tests taken within the last 2 to 3 years. A ton of forage with 10 percent CP uses 50 pounds of nitrogen, 10 pounds of phosphorus, 40 pounds of potassium and varying amounts of other chemical elements such as sulfur, calcium, magnesium, iron, zinc, copper, boron, manganese, molybdenum and chlorine.
All the listed elements are required for plant growth and if the required amounts are not available in the soil, less than a ton of forage is produced.
Most soils have enough nutrients, including nitrogen, to produce 1 to 2 tons of forage per acre. Improved grasses were developed for higher yield potentials and therefore need additional nutrients, especially nitrogen, phosphorus and potassium.
The recommended amount of fertilizer, based on a soil test, depends on the present nutrient content of the soil, the desired production level in tons per acre, and whether the pasture is used for hay, pasture or both.
Weed control
Weed control in pastures greatly enhances forage quantity and quality.
Adequate rainfall, large weed seed reserves in the soil and a long growing season are conducive for weed growth at the expense of forage production.
Many weed species germinate earlier than growth initiation of spring grass and steal soil nutrients and moisture from the desired forage. Only small amounts of forage are produced in weedy pastures, even with proper fertilization. Conversely, thick grass cover prevents weed growth.
In addition to maintenance of a thick stand of grass, weeds are controlled by shredding or with herbicides.
Herbicide application is usually the most economical method of weed control. In demonstration plots on improved pastures, 2 to 7 pounds of grass were produced for each pound of controlled weeds. In a native pasture, 1 pound of grass is produced for every 1 pound of controlled weeds.
Grazing management
There are several grazing systems and they all have their place. Using the same grazing system on all forage types, however, is not always profitable.
Rotational grazing systems are used on native rangeland to maintain or increase presence and vigor of desired plant species. Bermudagrass and bahiagrass don’t require rest periods for stand maintenance and plant vigor, so the purpose of rotation schedules is to control forage utilization and quality.
Increasing stocking rates on pastures decreases the quantity of forage available for each grazing animal. The opportunity for plant selection by the animal decreases and, in stockers, average daily gain (ADG) is less.
Gain per acre, however, is increased by heavier stocking rates, as long as some forage quality is present. In cow-calf operations, higher stocking rates decrease pasture cost per pound of calf gain. However, the cost savings will erode if the cows lose body condition scores.
For details on fitting the options together for a profitable pasture system, plan to attend Bade’s presentation at the Cattle Raisers Convention. Time will be available after the presentation for answering questions specific to your operation.
Managing Year-Round Pastures is excerpted from the February 2018 issue of The Cattleman magazine.